如果文档高于视口，则执行函数 [英] Execute function if document is taller than viewport

问题描述

这是我经历的一些非常奇怪的行为。我想只在文档高于视口时执行一个函数（即它溢出它并出现一个滚动条）。我使用这段代码：

This is some quite strange behaviour I experience. I want to execute a function only when the document is taller than the viewport (i.e. it overflows it and a scrollbar appears). I use this code:

var docH = $("document").height(),
    viewPortH = $("window").height();

if (docH > viewPortH) {
 // execute functions
}

但没有任何反应并且控制台返回：

But nothing happens and console returns:

未捕获的TypeError：无法读取null的属性'parent'

Uncaught TypeError: Cannot read property 'parent' of null

有谁知道问题是什么/我应该使用什么代码来查看文档是否比视口高？

Does anyone know what the problem is/what code I should use to see whether the document is taller than the viewport?

推荐答案

文件和窗口是对象不是选择器。

document and window are objects not selectors.

var docH = $(document).height(),
    viewPortH = $(window).height();

这篇关于如果文档高于视口，则执行函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！